Nothophaeotheca mirabibensis Crous, in Crous et al., Persoonia 46: 385 (2021)

MycoBank number: MB 839527; Index Fungorum number: IF 839527; Facesoffungi number: FoF 11468;

Etymology. Name refers to the collection site, namely the Mirabib inselberg in the Namib Desert, Namibia.

Mycelium consisting of smooth, hyaline to green-brown, septate, branched hyphae that give rise to microsclerotia, green-brown, globose to ellipsoid, 20–120 µm diam, containing endoconidia, globose, ellipsoid, green-brown, verruculose, muriform, initially in clusters of 2–6, eventually disarticulating into solitary, globose-ellipsoid conidia, thick-walled, verruculose to warty, 0–1-septate, ellipsoid-globose, (7–)8 – 9 × (6 –)7– 8 µm.

Culture characteristics — Colonies erumpent, surface folded, with sparse aerial mycelium and lobate, uneven margin, reaching 6 mm diam after 2 wk at 25 °C on MEA, PDA and OA surface and reserve iron-grey.

Typus. NAMIBIA, Gobabeb Namib Research Institute, Mirabib, on persistent inflorescence remains of Blepharis obmitrata (Acanthaceae), 19 Nov. 2019, P.W. Crous, HPC 3109 (holotype CBS H-24492, culture ex-type CPC 38944 = CBS 146980)

GenBank Accession Numbers: ITS: MZ064440, LSU: MZ064497, actA: MZ078152, tef1 (first part): MZ078228 and tef1 (second part): MZ078253.

Notes — Nothophaeotheca is related to Neophaeotheca, which is known to form a dematiaceous hyphomycetous morph with endoconidia. Two species of Neophaeotheca are presently known from twigs and leaves of Salicornia meyeriana in South Africa, and the humidifier of an air-conditioning system in Belgium (Abdollahzadeh et al. 2020). Although morphologically similar, Nothophaeotheca is phylogenetically distinct from Neophaeotheca. Based on a megablast search of NCBI’s GenBank nucleotide database, the closest hits using the ITS sequence had highest similarity to Neophaeotheca salicorniae (strain CPC 27406, GenBank NR_145401.1; Identities = 508/563 (90 %), 26 gaps (4 %)), Neophaeotheca triangularis (strain CBS 471.90, GenBank NR_137142.1; Identities = 417/459 (91 %), 21 gaps (4 %)) and Phaeothecoidea melaleuca (strain CPC 17223, GenBank HQ599594.1; Identities = 465/ 545 (85 %), 22 gaps (4 %)). Closest hits using the LSU sequence are Neophaeotheca triangularis (strain CBS 471.90, GenBank NG_057776.1; Identities = 839/856 (98 %), one gap (0 %)), Neophaeotheca salicorniae (strain CBS 141299, GenBank NG_058237.1; Identities = 813/834 (97 %), one gap (0 %)) and Fumagospora capnodioides (strain CBS 131.34, GenBank EU019269.1; Identities = 823 /860 (96 %), four gaps (0 %)). No significant hits were obtained when the actA and tef1 sequences were used in blastn and megablast searches.